How severe is CVE-1999-1222?

CVE-1999-1222 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-1999-1222 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-1999-1222?

CVE-1999-1222 primarily affects Microsoft Windows Nt. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-1999-1222?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-1999-1222 published?

CVE-1999-1222 was published on 1999-12-31 and last updated on 2026-06-16.

CVE-1999-1222

CVE-1999-1222 is a medium-severity vulnerability in Microsoft Windows Nt with a CVSS 2.0 base score of 5.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 2.0 base score 5.0)
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Windows Nt
Published: 1999-12-31
Last modified: 2026-06-16

Description

Netbt.sys in Windows NT 4.0 allows remote malicious DNS servers to cause a denial of service (crash) by returning 0.0.0.0 as the IP address for a DNS host name lookup.

Frequently asked questions

What is CVE-1999-1222?: Netbt.sys in Windows NT 4.0 allows remote malicious DNS servers to cause a denial of service (crash) by returning 0.0.0.0 as the IP address for a DNS host name lookup.
How severe is CVE-1999-1222?: CVE-1999-1222 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-1999-1222 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-1222?: CVE-1999-1222 primarily affects Microsoft Windows Nt. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-1999-1222?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-1999-1222 published?: CVE-1999-1222 was published on 1999-12-31 and last updated on 2026-06-16.

References

Affected products (2)

cpe:2.3:o:microsoft:windows_nt:4.0:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_nt:4.0:*:terminal_server:*:*:*:*:*

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